三种负载型氧化锌脱硫剂的除臭效能对比研究

针对环境中含硫恶臭物质的污染问题,以活性炭和石英微孔瓷粒为载体,采用浸渍法制备了一系列负载型氧化锌脱硫剂。研究了脱硫剂的除臭性能,并对其结构进行了分析。结果表明椰壳炭为载体所制备的脱硫剂除臭效能最佳,平均除臭时间为(34±3)min,但椰壳炭经改性处理后没有改善脱硫剂的除臭性能;椰壳炭表面分布着大量的孔,孔隙内分布着小颗粒的氧化锌,活性组分氧化锌的负载量越大,越有利于脱硫剂除臭活性的提高。     

载铜活性炭微球的制备及抗菌性能

以水热法合成的炭微球为原料,经KOH活化制备了活性炭微球,通过在氯化铜溶液中浸渍使铜吸附在活性炭微球上,得到载铜活性炭微球.采用XRD、SEM、TEM、EDS、XPS和N2吸脱附对载铜前后活性炭微球的结构和形貌进行了表征,并测试了其抗菌活性.研究表明,活性炭微球表面负载的铜是以离子形式存在,并且随着溶液中铜离子浓度的增加,载铜量增大,氨水的加入可明显提高铜的负载量.抗菌结果显示,载铜活性炭微球对大肠杆菌(E.coli)和金黄色葡萄球菌(S.aureus)具有良好的杀灭能力.因此,它作为一种抗菌材料有望在水处理、气体过滤和微生物污染等方面获得应用.     

化学活化法制备重质沥青基活性炭的研究

以重质沥青为原料，采用化学活化法制备重质沥青基活性炭，探究空气预氧化与硝酸钾预氧化、不同碱炭比及不同活化时间和活化温度对重质沥青基活性炭性能的影响，并采用碘吸附值与二氧化硫吸附量来确定活性炭的吸附性能。结果表明：在硝酸钾预氧化及碱炭比为4∶1的条件下，活化时间80min、活化温度850℃时制备的重质沥青基活性炭具有较为发达的微孔结构，碘吸附值为1052.2mg/g,二氧化硫吸附量为319.1mg/g。其性能优于物理活化法制备的活性炭，有望应用于吸附脱硫环保领域。     

高比表面积生物质活性炭的制备及其电化学性能研究

以核桃壳为生物质原料,KOH作为活化剂,在不同温度下(700,800,900℃),制备了低成本、高比表面积的核桃壳基生物质活性炭。通过SEM研究了活性炭的表面形貌;利用XRD、Raman研究了活性炭的石墨化程度;通过N2吸附/解吸附研究了活性炭的孔径结构,实验结果表明,在800℃下制备的活性炭AC-3-800,比表面积高达2 149m~2/g,平均孔径在1.93nm。超级电容器在0.5A/g电流密度下,比电容高达215F/g,并且表现出良好的循环稳定性,说明核桃壳基活性炭是一种良好的超级电容器电极材料。     

微波辅助碳酸钾活化制备玉米秆基活性生物炭

以碳酸钾为活化剂、少量活性炭为吸波剂,在氩气保护下对玉米秸秆进行微波加热制备活性生物炭。采用比表面积(BET)、扫描电镜和能谱(SEM和EDS)及化学检测的方法,研究了微波加热过程中生物炭孔隙度的变化规律,考察了温度、活化剂(K2CO3)配量、微波功率和保温时间对生物炭吸附性能及产率的影响。结果表明,微波加热制备活性生物炭的最佳条件为:温度650℃、活化剂(K2CO3)配量150%、微波功率700W、保温时间5min。此条件下获得产率为28.1%的活性生物炭,具有发达的多级孔隙结构,比表面积1036.7m2/g;而且此生物炭吸附性能较好,其中碘吸附值1238.7mg/g,亚甲基蓝吸附值254mg/g,优于木质净水用活性炭国家一级标准(GB/T 13804.3-1999)。     

水热炭化-KOH活化制备核桃壳活性炭电极材料的研究

以核桃壳为原料,经水热炭化-KOH活化制备活性炭,并将其用作超级电容器电极材料。采用低温氮气吸附、扫描电镜(SEM)及X射线光电子能谱(XPS)等手段系统研究核桃壳活性炭的微观结构及表面化学性质,并利用恒流充放电、循环伏安等探讨其对应电极材料的电化学性能。研究表明,在碱碳比为3∶1、活化温度为800℃、活化时间为1h的条件下,核桃壳水热炭经KOH活化可制备出比表面积为1 236m2/g、总孔容为0.804cm3/g、中孔比例为38.3%的活性炭。该核桃壳活性炭用作电极材料在KOH电解液中具有优异的电化学特性,其在50mA/g电流密度下的比电容可达251F/g,5 000mA/g电流密度下的比电容为205F/g,且具有良好的循环稳定性,1 000次循环后比电容保持率达92.4%,是一种比较理想的超级电容器电极材料。核桃壳活性炭优异的电化学性能与其相互贯通的层次孔结构和独特的含氧表面密切相关。     

纳米SiO2载银抗菌剂的研究

以化学沉淀法制备得到多孔纳米SiO2,采用吸附法在其表面负载银,用载银的粉体抑菌囤直径表征抗菌性能。研究了吸附时间、硝酸银浓度及吸附温度与负载量的关系,并考查了焙烧温度与抗菌性能的关系。     

磷酸法活化煤焦油渣制备活性炭研究

研究了以陕西煤焦油渣作为原料,用磷酸作为活化剂,在400～1000℃的条件下经一步炭活化法制备活性炭。研究了炭活化温度、时间、料剂比对煤焦油渣制备活性炭吸附性能及孔结构的影响。实验结果表明炭活化温度、炭活化时间主要影响活性炭产品的得率,高温和长时间会导致更多的碳损失;活性炭的吸附性能及孔结构主要受炭活化温度和料剂比影响。最佳活化工艺条件为850℃、3h、1∶3。通过其活性炭表面孔径分布及表面官能团含量变化表征,用磷酸浸泡煤焦油渣制备活性炭有利于大、中孔结构的产生,其最佳活化条件下孔径分布约在20～100nm。     

MoS2/核桃壳活性炭复合纳米材料的制备及其电催化析氢性能研究

以钼酸铵为钼源、硫脲为硫源,使用核桃壳活性炭通过水热法成功制备二硫化钼(MoS_2)/核桃壳活性炭复合纳米材料。研究了MoS_2含量对复合纳米材料形貌、尺寸及电化学性能的影响,通过X射线粉末衍射仪、冷场发射扫描电子显微镜、比表面积及孔隙度分析仪、线性扫描伏安法对复合纳米材料的结构、形貌、电化学性能进行分析和表征。结果表明,MoS_2质量分数为80%的MoS_2/核桃壳活性炭复合纳米材料的电催化析氢反应活性最好。     

KOH活化法制备煤基活性炭及其吸附性能研究

研究了以无烟煤为原料,通过预炭化、再采用KOH活化法制备煤基活性炭的工艺。利用场发射扫描电子显微镜(SEM)研究了活性炭的显微结构,并测试了活性炭对甲基橙(MO)的吸附性能。结果表明:无烟煤炭化产物与KOH质量比(炭碱比)、活化温度、活化时间对煤基活性炭显微结构及吸附性能有显著影响。在炭碱比为1∶1、活化温度为900℃、活化时间1h的条件下,能制备出吸附性能良好的活性炭材料,吸附15min时对MO的吸附率可达到89.6%。     

Production of granular activated carbon from waste walnut shell and its adsorption characteristics for Cu(2+) ion

Production of granular activated carbon by chemical activation has been attempted employing walnut shells as the raw material. The thermal characteristics of walnut shell were investigated by TG/DTA and the adsorption capacity of the produced activated carbon was evaluated using the titration method. As the activation temperature increased, the iodine value increased. However, a temperature higher than 400 degrees C resulted in a thermal degradation, which was substantiated by scanning electron microscopy (SEM) analysis, and the adsorption capacity decreased. Activation longer than 1h at 375 degrees C resulted in the destruction of the microporous structure of activated carbon. The iodine value increased with the increase in the concentration of ZnCl2 solution. However, excessive ZnCl2 in the solution decreased the iodine value. The extent of activation by ZnCl2 was compared with that by CaCl2 activation. Enhanced activation was achieved when walnut shell was activated by ZnCl2. Applicability of the activated carbon as adsorbent was examined for synthetic copper wastewater. Adsorption of copper ion followed the Freundlich model. Thermodynamic aspects of adsorption have been discussed based on experimental results. The adsorption capacity of the produced activated carbon met the conditions for commercialization and was found to be superior to that made from coconut shell.     

Fabrication of magnetic activated carbon by carbothermal functionalization of agriculture waste via microwave-assisted technique for cationic dye adsorption

The agriculture shell wastes were carbothermally converted to magnetic activated carbon by a microwave-assisted decoration of iron oxide nanoparticles onto the shell surface. The influence of ternary catalytic mixtures, including zinc, iron II and III chlorides on the cationic dye adsorption efficiency was addressed by the composite impregnations onto the almond or walnut shell powders, explored to the carbonization. The efficiency was maximized by determination the proportions of used salts. The best results were obtained with loading FeCl₃ onto the walnut shell in which the proportion of salt was 50%. Although the load of magnetic particles onto the adsorbent normally lead to decrease in efficiency, the prepared powder exhibited the appropriate performance above 99%. It should be point out that the dye adsorption efficiency of magnetic activated carbons fabricated by carbothermal functionalization was 7–10% higher than those produced in the nitrogen atmosphere. The adsorbent displayed the nano-porous structure with average pore diameter about 2 nm, providing a surface area around 1000 m²·g⁻¹ for the removal of dye in a dynamic system. The maximum adsorption capacity was determined to be 130 mg·g⁻¹ in the neutral condition.     

利用核桃壳制备高比表面积活性炭电极材料的研究

以核桃壳为原料,采用KOH活化法制备活性炭,并将其用作超级电容器电极材料。利用N2吸附和扫描电镜(SEM)表征活性炭的孔结构及表面形貌,系统研究碱炭比(KOH与核桃壳炭化料的质量比)对活性炭孔结构的影响,并采用恒流充放电及循环伏安等测定核桃壳活性炭电极材料在3mol/L KOH电解液中的电化学性能。结果表明,随着碱炭比的增大,活性炭的比表面积、总孔容及中孔比例先逐渐增大后稍有减小。当活化温度为800℃,活化时间为1h,碱炭比为4时,可制备出比表面积为2404m2/g,总孔容为1.344cm3/g,中孔比例为28.6%,孔径分布在0.7~3.0nm之间的高比表面积活性炭。该活性炭用作超级电容器电极材料具有良好的大电流放电特性和优异的循环性能,电流密度由50mA/g提高到5000mA/g时,其比电容由340F/g降低到288F/g,经1000次循环后,比电容保持率为93.4%。     

Removal of hexavalent chromium from aqueous solution using activated carbon prepared from walnut shell biomass through alkali impregnation processes

Walnut (Juglans regia) is a commonly used nutrient industrial crop but the shell of the walnut has no economic value. Hence to revamp the waste walnut shell biomass to useful product, activated carbon (AC) was prepared from J. regia shells by impregnating with NaOH. Different ACs were prepared by varying the impregnation ratio of char:NaOH as 1:1 (AC1), 1:3 (AC2), and 1:5 (AC3). The effect of impregnation ratios on the adsorptive properties of ACs for the adsorption of hexavalent chromium [Cr(VI)] was studied. The ACs were characterized by SEM, surface functionality, and zero point charge. Langmuir, Freundlich, Temkin, and Dubinin–Radushkevitch isotherm were used to interpret the batch equilibrium data. The adsorption of Cr(VI) onto ACs followed Langmuir isotherm model. Kinetic data followed pseudo second-order rate equation. Intraparticle diffusion model and Boyd plot were used to study the mechanism of the adsorption reaction. The adsorption was both by film diffusion and intraparticle diffusion. The rate-controlling step was predicted as external mass transfer. Thermodynamic parameters were also estimated. Overall, AC with higher impregnation ratio (AC3) possessed better adsorption properties compared to AC2 and AC1.     

Adsorptive removal of chlorophenols from aqueous solution by low cost adsorbent--Kinetics and isotherm analysis

Adsorptive removal of parachlorophenol (PCP) and 2,4,6-trichlorophenol (TCP) from aqueous solutions by activated carbon prepared from coconut shell was studied and compared with activated carbon of commercial grade (CAC). Various chemical agents in different concentrations were used (KOH, NaOH, CaCO(3), H(3)PO(4) and ZnCl(2)) for the preparation of coconut shell activated carbon. The coconut shell activated carbon (CSAC) prepared using KOH as chemical agent showed high surface area and best adsorption capacity and was chosen for further studies. Batch adsorption studies were conducted to evaluate the effect of various parameters such as pH, adsorbent dose, contact time and initial PCP and TCP concentration. Adsorption equilibrium reached earlier for CSAC than CAC for both PCP and TCP concentrations. Under optimized conditions the prepared activated carbon showed 99.9% and 99.8% removal efficiency for PCP and TCP, respectively, where as the commercially activated carbon had 97.7% and 95.5% removal for PCP and TCP, respectively, for a solution concentration of 50mg/L. Adsorption followed pseudo-second-order kinetics. The equilibrium adsorption data were analysed by Langmuir, Freundlich, Redlich-Peterson and Sips model using non-linear regression technique. Freundlich isotherms best fitted the data for adsorption equilibrium for both the compounds (PCP and TCP). Similarly, acidic pH was favorable for the adsorption of both PCP and TCP. Studies on pH effect and desorption revealed that chemisorption was involved in the adsorption process. The efficiency of the activated carbon prepared was also tested with real pulp and paper mill effluent. The removal efficiency using both the carbons were found highly satisfactory and was about 98.7% and 96.9% as phenol removal and 97.9% and 93.5% as AOX using CSAC and CAC, respectively.     

氯化铜/活性炭复合电极的制备及性能的研究

以酚醛树脂为活性炭基体,采用化学掺杂法掺杂氯化铜,制备氯化铜／活性炭复合电极材料。通过物理吸附考察了金属氯化铜的存在下不同活化时间对金属复合活性炭孔径分布的影响,实验表明活化时间越长,比表面积越大,中孔含量越高。通过透射电镜和X射线衍射对复合电极的微观结构进行了研究,表明金属铜以纳米级均匀分散在活性炭中。通过比较活性炭电极和复合电极的电化学性能,说明掺杂金属铜可以有效提高比电容,并对充放电机理进行了探讨。     

Effect of moisture on H(2)S adsorption by copper impregnated activated carbon

The aim of this study is to investigate the effect of moisture on adsorption efficiency of hydrogen sulfide (H(2)S) by impregnated activated carbon (IAC). Copper(II) nitrate was used as an impregnant. Two humidification conditions of IAC, pre-moistened and gas stream containing moisture, were studied. The experimental results revealed that the copper species onto the IAC was suggested to be Cu(OH)(2) that deposited on activated carbon during the impregnation process. The adsorption mechanism of H(2)S by copper impregnated IAC was proposed, involving physic-sorption and chemical reactions. Moreover, the H(2)S breakthrough capacity decreased with increasing the relative humidity of gas stream. The causes were attributed to three points as follow: the competition adsorption occurred between moisture and H(2)S; the copper(II) species reduced to copper(I) species leading to IAC deactivation; and the rate of chemical reaction restrained by moisture.     

Preparation and characterization of the carbon–Microsilica composite sorbent

In this paper, Microsilica, one kind of industry solid waste, was utilized firstly to prepare carbon–Microsilica composite sorbent with core–shell structures from a partial carbonization, mixture, and sulfonation process. The prepared composite sorbent was characterized with XPS, FT-IR, SEM, XRD and gas sorption experiments. The characterization results indicated BET surface area (S_BET) and total pore volume (V_total) of the prepared composite sorbent enhance 255% and 136% than Microsilica, respectively, and an abundant of oxygen functional groups, such as carboxyl and sulfonic groups, were introduced into the surface of the prepared composite sorbent. The adsorption capacity of the prepared composite sorbent for methylene blue (MB) and Cr(VI) also was investigated and compared with Microsilica and activated carbon, the results shown that the adsorption capacity of the prepared composite sorbent for methylene blue and Cr(VI) enhance 406.6% and 657.5% than Microsilica, and reach about 70.0% and 72.3% of activated carbon adsorption capacity, respectively. This paper proposed a new approach of comprehensive utilization of Microsilica with a uncomplicated process, and the prepared carbon–Microsilica composite sorbent with excellent adsorbent performance could be used as a potential substitute of activated carbon for heavy metal ion or organic dye adsorption in waste water.     

Functionalization of powdered walnut shell with orthophosphoric acid for Congo red dye removal

This study investigates the adsorption of Congo red dye on walnut shell powder based activated carbon in batch process (WNAA). Walnut shell powder was carbonized by treating with phosphoric acid (H₃PO₄), and the adsorbent was characterized using Fourier Transform-Infrared spectrophotometer (FT-IR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), and pH point of zero charge (pH_pzc), respectively. Operational parameters such as contact time, initial dye concentration, and pH were investigated using batch-adsorption techniques. The adsorption uptake was found to increase with increase in initial dye concentration and contact time. The optimum CR dye uptake was observed at pH 3.12 corresponding to 94.53% removal. Pseudo-first-order, pseudo-second-order, Elovich, and Intraparticle diffusion kinetic models were used to test the adsorption data. The pseudo-second order exhibited the best fit out of the four kinetic models used. Equilibrium data were fitted to the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models. Langmuir model fitted the adsorption data most with maximum monolayer coverage of 40?mg/g. Thermodynamic parameters such as Gibbs free energy, enthalpy, entropy, and the activation energy were determined. It was found that Congo red dye adsorption was spontaneous and endothermic. 0.02M Hydrochloric acid was used to regenerate the adsorbent prepared, and the regenerated adsorbent was used for dye adsorption. Congo red dye adsorption capacity ranged from 90% to 93% at three consecutive times. This study has shown that walnut shell is a good adsorbent in the treatment of Congo red dye from aqueous solutions.